Pressure contact fuse clip



March 13, 1934. J. G. JACKSON PRESSURE CONTACT FUSE CLIP Filed Dec. 8, 1930 INVENTOR 1762?; & aka/(.5071

ATTORN EYrS' Patented Mar. 13, 1934 UNE E E STATES assess? PATENT @FFEQE PRESSURE CONTACT FUSE CLEP tion of Michigan Application December 8, 1930, Serial No. 500,943

8 Claims.

This invention relates generally to pressure contact clips and more particularly to fuse holding contact clips of the type having spring fingers for gripping the usual annular terminal members on the ends of cartridge fuses.

One of the principal objects of this invention is to provide a pressure contact fuse clip distinguished from conventional design in that the resilient fingers are substantially straight resulting in a line contact between the fingers and fuse terminals.

With the foregoing arrangement, the fuse terminals are not only firmly clamped between the fingers, but the resilient qualities of the latter are preserved since the usual ferrule or intermediate curved portions of the fingers for receiving the ends of the fuse are eliminated and as a consequence, it is not necessary to separate the fingers to as great an extent upon assembling the fuse therewith. Moreover, by reason of the elimination of the conventional curved fingers, insertion and removal of the fuse is facilitated and the fastening means for attaching the contact clip to a support is rendered more accessible and may be manipulated without unduly spreading the fingers from their normal position.

Another advantageous feature of this invention resides in the provision of a construction wherein a stop is provided on the contact clip for positioning the fuse in assembled relation therewith and wherein the resilient fingers are fashioned in such a manner as to cooperate with the stop to retain a fuse in the contact clip.

The foregoing, as well as other objects, will be made more apparent as this description proceeds, especially when considered in connection with the accompanying drawing, wherein:

Figure l is a side elevational view of a pair of contact clips constructed in accordance with this invention Figure 2 is a sectional view taken substantially on the line 2-2 of Figure l; and

Figure 3 is a view similar to Figure 2 showing the configuration of the contact clip prior to the insertion of a fuse;

Figure 4 is a plan view of a blank from which the contact clips are formed;

Figure 5 is a view similar to Figure 2 showing a slightly modified form of construction.

Referring now to the drawing, it will be noted that there is illustrated in Figure 1 a pair of contact clips 10 and ll constructed in accordance with this invention and cooperating with each other to firmly clamp a cartridge fuse 12 in assembled relation. The cartridge fuse 12, shown herein for the purpose of illustration, is of conventional construction comprising a circular body portion 13 having annular terminal members 14 and 15 upon the ends thereof for engagement with the contact clips 10 and 11.

Referring now more in detail to the particular construction of the contact clips, it will be noted from Figures 2 and 3 that the same are substantially U-shaped in cross section with the base portions 16 thereof clamped to suitable current carrying members 17 by means of the fastening elements 18. Each of the contact clips is developed from a suitable blank shown in Figure 4 and the leg portions 19 of the U-shaped contact clip are substantially straight and are inclined inwardly toward each other terminating in outwardly flared portions 20 which serve to guide the terminal portions of the fuse into position between the legs 19 which are hereinafter refeJred to as resilient fingers. The extent of inclination of the resilient fingers 19 from the base portions 16 depends entirely upon the diameter of the terminal fuse members with which the contact clips are adapted to be used. clearly shown in Figure 3, the distance between the upper portions of the flexible fingers is substantially less than the diameter of the terminal members on the fuse, with the result that insertion of the terminal members on the fuse between the flexible fingers causes the latter to separate slightly from their normal position. Separation of the flexible fingers from their normal position places the same under tension and in their effort to return to their original position, exert a pressure upon diamet rically opposite sides of the terminal members firmly clamping the same in the contact clips.

As previously stated, the fiexible fingers 19 are substantially straight from one end to the other and are so fashioned that when the terminal members of the fuse are in assembled relation therewith as shown in Figure 2, the flexible fingers are tangent to the annular surface of the terminal member with the result that a line contact between the fingers and terminal members is provided. The construction is such that while considerable pressure is exerted upon diametrically opposite sides of the terminal members on the fuse to retain the same in the contact clips, never theless, the extent of separation of the flexible fingers upon inserting the fuse therebetween is relatively small, with the result that insertion and removal of the fuse may be accomplished with little effort compared to the pressure exerted upon the fuse by the fingers. Moreover, by reason of the above arrangement the fastening means 18 is rendered more accessible and may be manipu lated without unduly separating the fingers 19. In this connection it will be noted that the fastening means 18 comprises a threaded element 21 and a clamping nut 22 threaded upon the element 21 within the retaining contact clips. By arranging the fastening means as set forth, the latter may be used not only for clamping the contact clips to their supports, but also as a stop for engaging the terminal members on the fuse to position the latter between the fingers 19 at a point where maximum pressure is exerted. As shown particularly in Figure 2, the fastening means functions to position the terminal members on the fuse within the-contact clips in such a manner that the fingers exert a pressure upon the terminal members at points spaced outwardly from the longitudinal axis of the fuse with the result that engagement of the terminal members with the stops is somewhat automatically effected.

The modified form of contact clip iliustrat=d in Figure 5 differs from the one previously described in that the contact clip is so fashioned that the resilient fingers 25 thereof are arranged substantially parallel to each other when the fuse terminal is clamped therebetween. I'he arrange ment is such as to permit a greater variation in the position of the fuses relative to the fingers Without interfering with the line contact between the fingers and fuse terminal. It will further be observed fro-m Figure 5 that the outer end portions of the fingers 25 are bent inwardly slightly to provide obstructions 26 for preventing accidental disengagement of the fuse terminal from the clip. The extreme outer ends of the fingers 25 are flared outwardly to facilitate insertion of the fuse terminal between the fingers.

Repeated laboratory tests have disclosed that contact clips constructed in accordance with this invention and fashioned of the same material as the conventional type of contact clip possess from forty to sixty per cent. greater conductivity than the ferrule type of clip. Moreover, contact clips of the type illustrated herein retain their inherent clamping action over a comparatively long period of use and are more economical in manufacture owing to the relative simplicity thereof. Furthermore, it will be seen that the foregoing contact clips may be more readily attached to and detached from their support owing to the accessibility of the fastening means which may be manipulated without separating or otherwise interfering with the spring fingers.

Thus, from the foregoing it will be observed that I have provided an improved fuse clip construction designed to retain its inherent clamping action over a long period of use and one which lends itself to economical manufacture owing to the simplicity thereof, It will further be seen that I have provided an improved clip construction which may be more readily attached to and detached from its support owing to the accessibility of the f asiening means, and which precludes the necessity of separating the spring fingers during installation or removal of the clip.

What I claim as my invention is:

l. A clip for effec ing line contact with a cylindrica-l contact member, having a base and having flat sides projecting from the base so as to be tangent to and have line contact only with said cylindrical member at points at opposite ends of a chord less than the diameter of the cylindrical member, said sides being so inclined as to press the cylindrical member toward ihe base while effecting the line contact aforesaid.

2. An inherently resilient clip for effecting line contact with a cylindrical contact member, having a base and having substantially fiat sides projecting from the base so as to be tangent to and have line contact only with said cylindrical member at points at opposite ends of a chord disposed outwardly relative io a diametric line parallel to the base of the clip, said sides being fashioned to force the cylindrical member toward the base while exerting the line pressure aforesaid upon the cylindrical member.

3. A pressure contact fuse clip formed from spring metal st ck and designed to grip a fuse ferrule of the circular type, said clip having a base and opposed gripping fingers at opposite ends of said base, the construction of the clip being such that the fingers resist separation but are yieldable to permit of the insertion therebetween of a fuse ferrule, said fingers being siraight so as to be tangent to and have line contact only with said ferrule and converging from the base so that they will press the ferrule toward the base.

4. In a fuse clip assembly, a current carrying member, a fuse clip having a base on said member and having flat sides projecting from the base so as to be tangent to and have line contact only with a fuse ferrule of circular formation, and a connection between the clip and member engaging the base and providing a stop for the fuse ferrule aforesaid, the said sides being fashioned to hold the ferrule upon the stop regardless of the position thereof relative to the base while maintaining the line contact aforesaid.

5. In a fuse clip assembly, a current carrying member, a fuse clip having a base on said member and having fiat sides projecting from the base so as to be tangent to and have line contact only with a fuse ferrule of circular formation, and a connection between the clip and member engaging the base and including means providing a stop for the fuse ferrule aforesaid, the said sides being fashioned to hold the ferrule upon the stop while maintaining the line contact aforesaid.

6. A clip for effecting line contact with a cylindrical contact member, having a base and a stop in fixed relation to the base and having resilient sides presenting flat surfaces for pressure engagement with the cylindrical con act member, the sides being so spaced and inclined as to press the cylindrical member inwardly toward the stop while effecting contact between the sides and the cylindrical member.

7. A pressure contact fuse clip for effecting coni act with and retaining the cylindrical contact member of a fuse, having a base portion and adapted to be assembled with a stop for the fuse contact in substantially fixed relation to the base and resilient conducting arms upon the clip adapted to present fiat surfaces to the cylindrical contact member and so formed as to provide an inwardly extending portion to hold the cylindrical contact in engagement with the clip.

8. A pressure contact fuse clip for effecting contact with and retaining the cylindrical contact member of a fuse, having resilient conducting arms upon the clip adapted to present flat sur faces to the cylindrical contact member and so formedas to provide an inwardly extending portion to hold the cylindrical contact in engagement with the clip.

JOHN G. JACKSON. 

